Medtronic
 
 

Insertable
Cardiac Monitor

FAQ's

Q. Is Magnetic Resonance Imaging (MRI) safe when a patient has a Reveal®?

A. Magnetic and radio frequency fields produced by MRI may adversely affect the data being stored by the Reveal Insertable Cardiac Monitor (ICM). And since the ICM contains ferromagnetic components, the strong magnetic field of the MRI system may apply a mechanical force on the device. The patient may be able to feel this. While the magnetic force on the device does not represent a safety hazard, the patient should be made aware of the possibility, to avoid undue concern.

Q. What about Seizures & Syncope?

A. Despite different underlying mechanisms, syncopal events and seizures may both be accompanied by involuntary movements of the body. While epileptic seizures are caused by abnormal neuron firing in the brain, convulsive movements in syncope are a result of reduced blood flow to the brain and the resulting cerebral anoxia. The presence of conditions that mimic seizure activity can make convulsive syncope difficult to differentiate from epilepsy.

Clinical research suggests that 20% or more of patients with intractable epilepsy do not have the neurological disorder.1 This misinterpretation has important implications:

  • The underlying disease may not receive proper treatment
  • Some cardiac causes of syncope carry a considerable mortality risk
  • Bradycardia may be aggravated by some ion channel active anti-epileptic drugs (AEDs)
  • A diagnosis of epilepsy may lead to significant psychosocial consequences2

This diagnostic challenge strongly suggests a collaborative approach between cardiologists and neurologists. For research on the misdiagnosis of seizure-like episodes, click here.

Q. What about SUDEP - Sudden Unexpected Death in Epilepsy?

A. Among patients with a confirmed epilepsy diagnosis, many seizures are associated with changes in heart rate and/or rhythm. Many of these changes are physiological and benign, but some are potentially life-threatening. According to John Duncan, et al., “…sudden unexpected death in epilepsy could be due to fatal neurogenic cardiac arrhythmias.” 3

To learn more about the potential role of cardiac arrhythmias in sudden unexpected death in epilepsy, please click here.

References
  1. Sander JWAS. Epilepsy: getting the diagnosis right. BMJ. 1997;314:158.
  2. Bergfeldt L. Differential diagnosis of cardiogenic syncope and seizure disorders. Heart. 2003;89:353-358.
  3. Rugg-Gunn FJ, Simister RJ, Squirrell M, Holdright DR, Duncun JS. Cardiac arrhythmias in focal epilepsy: a prospective long-term study. Lancet. 2004;364:2212-2219.

Additional Information